Persons with serious mental illness (SMI) are at increased risk for HIV/AIDS. The relative risk of HIV/AIDS is at least five times greater in SMI as the general Medicaid population in Philadelphia, and we estimate that up to 7% of the SMI population is also HIV seropositive. SMI persons reported more transmissions through heterosexual contact and injection drug use (IDU), and SMI women have more sex with men who have sex with men (MSM) than in the general population. A cost study showed that SMI with HIV had much higher health care costs than non-SMI persons with HIV and non-HIV persons with SMI. There is concern that HIV positive SMI persons may be a greater risk for poor treatment adherence, increasing risk for poorer outcomes and development of treatment resistant virus, and also placing others at greater risk. Substance use and depression have been shown to interfere with HIV treatment adherence. Involvement of advance practice nurses (APNs) has been previously shown to improve outcomes for persons with HIV/AIDS. Since case managers (CMs) are already involved with coordinating mental health, social, and other services for this population and have specialized expertise in providing those services, we believe that an integrated services model that integrates nursing and case management will result in demonstrably better HIV treatment outcomes using CD4 and viral load as indicators, and significantly reduced risk behaviors using standardized behavioral self-reports. Participants will be recruited from among those already in treatment for SMI in one of four large urban CMHC's in Philadelphia. Using a longitudinal (baseline, 6,12, and 24 months) experimental and control group design, we will randomly assign 300 participants to the intervention or control groups. Participants will be screened for active substance abuse and depression, randomized, and experimental participants will receive an integrated intervention tailored to the communication and comprehension of the individual, and will include memory aid devices, education regarding side effects and other treatment aspects, and active community outreach. For those who fail to adhere using the basic intervention, a treatment cascade that increases in intensity will be implemented. Using 80% adherence as a target, the cascade will include involvement of family and significant others in prompting participants through use of beepers, cellphones, and for those who still fall short of 80% adherence, directly observed therapy.